Cable Connectors for Use Downhole

ABSTRACT

A cable system for use downhole includes a connector assembly having a body and a bore formed therethrough; a conductor disposed through the bore of the connector assembly; and a first insulation layer disposed around the conductor. An insulator tube is disposed around the conductor and has an end attached to the first insulation layer. The insulator tube may be made of a thermoplastic material. A graphite containing sealing member is disposed in the bore and disposed between the insulator tube and the body of the connector assembly.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit to U.S. Provisional Application63/068,487, filed on Aug. 21, 2020; and this application herebyincorporates herein U.S. Provisional Application 63/068,487, and allamendments thereto as if set forth herein in its entirety.

BACKGROUND 1. Field of Inventions

Certain aspects of the present disclosure generally relate to a powercable for use downhole. In one embodiment, the power cable is used in ahigh temperature environment to transmit power to a downhole tool. Inparticular, aspects of the present disclosure relate to cable connectorsfor use in a high temperature environment to transmit power to adownhole tool.

2. Description of Related Art

Many wells use an artificial lift or pumping system to produce wellborefluids deep within the earth to surface. One such type of artificiallift system is referred to as an Electric Submersible Pump (“ESP”). AnESP system typically includes the following downhole components: amulti-stage centrifugal pump, an electric motor, and a main power cablefor sending electric power downhole to the motor.

A motor lead extension (“MLE”) is spliced into the main cable forsupplying power to the motor. The end of the MLE has a connectorassembly typically referred to as a pothead. The pothead contains theterminals that plug into the motor, which is analogous to an extensioncord plugging into a wall socket, to complete the transfer of electricpower to the motor. In addition to providing an electrical connection tothe motor, the pothead is typically designed to prevent any wellborefluids from entering the motor and to prevent the motor's highdielectric mineral oil, used to lubricate and insulate the motor, fromleaking out.

One of the most challenging types of oil well applications is known asSteam Assisted Gravity Drainage (“SAGD”). The main reason thisapplication is difficult when compared to other more conventionalapplications is the high temperatures at which the SAGD wells operate.Most conventional wells do not exceed 110 oC. However, in SAGD wells,bottom hole temperatures (“BHT”) can range from 180 oC to as high as 260oC. When an ESP is installed to produce fluids from the well, theequipment's operating temperatures can be as much as 50 oC higher thanthe BHT. Thus, an ESP system in a SAGD well may have to operate at 300oC or above. At these significantly higher temperatures, standard ESPequipment will not function for run times that are economical to theoperators of these wells.

Standard ESP equipment may have shortened run lives due to thetemperature rating of the insulation systems contained within the motorand MLE. For example, the pothead of a conventional ESP system commonlyuses an elastomeric compound to seal the outside surfaces of the threeinsulated conductors. However, at the expected operating temperatures ofa SAGD well, the standard polyimide insulation is not suitable. There isa need, therefore, for new, unique designs to overcome the temperaturelimitations of standard ESP equipment.

Various cable connectors and methods for connecting electrical cableshave been proposed and utilized, including those disclosed in some ofthe patents and/or publications on the front of this patent. However,those methods and assemblies lack the combination of steps and/orfeatures of the methods and/or assemblies disclosed herein. Furthermore,it is contemplated that the methods and/or assemblies disclosed hereinsolve many of the problems that prior art methods and assemblies havefailed to solve.

SUMMARY

In one embodiment, a cable system for use downhole includes a connectorassembly having a body and a bore formed therethrough; a conductordisposed through the bore of the connector assembly; a first insulationlayer disposed around the conductor; an insulator tube disposed aroundthe conductor and having an end attached to the first insulation layer,the insulator tube comprising a thermoplastic material; and a graphitecontaining sealing member disposed in the bore and disposed between theinsulator tube and the body of the connector assembly.

In another embodiment, a submersible pumping system for use downholeincludes a motor; a pump powered by the motor; a tubing connected to thepump; and a cable disposed along the tubing and configured to providepower to the motor. In one embodiment, the cable includes a connectorassembly having a body and a bore formed therethrough; a conductordisposed through the bore of the connector assembly; a first insulationlayer disposed around the conductor; an insulator tube disposed aroundthe conductor and having an end attached to the first insulation layer,the insulator tube comprising a thermoplastic material; and a graphitecontaining sealing member disposed in the bore and disposed between theinsulator tube and the body of the connector assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example artificial lift system, according toaspects of the present disclosure.

FIG. 2 illustrates an exemplary cable connected to a pothead.

DETAILED DESCRIPTION 1. Introduction

A detailed description will now be provided. The purpose of thisdetailed description, which includes the drawings, is to satisfy thestatutory requirements of 35 U.S.C. § 112. For example, the detaileddescription includes a description of inventions defined by the claimsand sufficient information that would enable a person having ordinaryskill in the art to make and use the inventions. In the figures, likeelements are generally indicated by like reference numerals regardlessof the view or figure in which the elements appear. The figures areintended to assist the description and to provide a visualrepresentation of certain aspects of the subject matter describedherein. The figures are not all necessarily drawn to scale, nor do theyshow all the structural details, nor do they limit the scope of theclaims.

Each of the appended claims defines a separate invention which, forinfringement purposes, is recognized as including equivalents of thevarious elements or limitations specified in the claims. Depending onthe context, all references below to the “invention” may in some casesrefer to certain specific embodiments only. In other cases, it will berecognized that references to the “invention” will refer to the subjectmatter recited in one or more, but not necessarily all, of the claims.Each of the inventions will now be described in greater detail below,including specific embodiments, versions, and examples, but theinventions are not limited to these specific embodiments, versions, orexamples, which are included to enable a person having ordinary skill inthe art to make and use the inventions when the information in thispatent is combined with available information and technology. To theextent a term used in a claim is not defined below or in representationsto the Patent and Trademark Office (PTO), it should be given thebroadest definition persons having skill in the art have given that termas reflected in at least one printed publication, dictionary, or issuedpatent.

2. Specific Embodiments in the Drawings

The drawings presented herein are for illustrative purposes only and donot limit the scope of the disclosure. Rather, the drawings are intendedto help enable one having ordinary skill in the art to make and use theassemblies disclosed herein.

FIG. 1 illustrates an artificial lift system (ALS) 25 pumping productionfluid, such as bitumen 8 p (also known as tar sand or oil sand), from asteam assisted gravity drainage (SAGD) well 1, according to oneembodiment of the present disclosure. Alternatively, the productionfluid may be heavy crude oil or oil shale. The ALS 25 may include amotor driver 25 s, a power cable 14, and a downhole assembly 25 d. TheSAGD well 1 may include an injection well 1 i and a production well 1 p.Each well 1 i, p may include a wellhead 2 i, p located adjacent to asurface 4 of the earth and a wellbore 3 i, p extending from therespective wellhead. Each wellbore 3 i, p may extend from the surface 4vertically through a non-productive formation 6 d and horizontallythrough a hydrocarbon-bearing formation 6 h (aka reservoir).Alternatively, the horizontal portions of either or both wellbores 3 i,p may be other deviations besides horizontal. Alternatively, theinjection well 1 i may be omitted and the ALS 25 may be used to pumpproduction fluid from other types of adverse production wells, such ashigh temperature wells.

Surface casings 9 i, p may extend from respective wellheads 2 i, p intorespective wellbores 3 i, p and each casing may be sealed therein withcement 11. The production well 1 p may further include an intermediatecasing 10 extending from the production wellhead 2 p and into theproduction wellbore 3 p and sealed therein with cement 11. The injectionwell 1 i may further include an injection string 15 having an injectiontubing string 15 t extending from the injection wellhead 2 i and intothe injection wellbore 3 i and having a packer 15 p for sealing anannulus thereof.

A steam generator 7 may be connected to the injection wellhead 2 i andmay inject steam 8 s into the injection wellbore 3 i via the injectiontubing string 15 t. The injection wellbore 3 i may deliver the steam 8 sinto the reservoir 6 h to heat the bitumen 8 p into a flowing conditionas the added heat reduces viscosity thereof. The horizontal portion ofthe production wellbore 3 p may be located below the horizontal portionof the injection wellbore 3 i to receive the bitumen drainage 8 p fromthe reservoir 6 h.

A production string 12 may extend from the production wellhead 2 p andinto the production wellbore 3 p. The production string 12 may include astring of production tubing 12 t and the downhole assembly 25 dconnected to a bottom of the production tubing. A slotted liner 13 maybe hung from a bottom of the intermediate casing 10 and extend into anopen hole portion of the production wellbore 3 p. The downhole assembly25 d may extend into the slotted liner 13. Alternatively, the downholeassembly 25 d may extend to a bottom of the intermediate casing 10 or bedisposed in the vertical portion of the production wellbore 3 p.

The downhole assembly 25 d may include a submersible electric motor 20,a motor head 21, a motor seal 22, and a pump 24. Housings of thecomponents may be connected and sealed, such as by flanged connections.The flanged connections may longitudinally and torsionally connect thecomponent housings. Shafts of the components may be torsionallyconnected, such as by shaft couplings. The shaft couplings may besplined couplings. The shaft couplings may also transfer thrust loadingfrom the pump 24 to the motor seal 22.

The pump 24 may be centrifugal, such as a radial flow or mixedaxial/radial flow centrifugal pump. The pump 24 may include one or morestages. Each stage may include an impeller and a diffuser. Each impellermay be longitudinally and torsionally connected to the pump shaft andeach diffuser may be longitudinally and torsionally connected to thepump housing. Rotation of each impeller by the pump shaft may impartvelocity to the bitumen 8 p and flow through the stationary diffuser,which may convert a portion of the velocity into pressure. The pump 24may deliver the bitumen 8 p to the production tubing 12 t via adischarge head. Alternatively, the pump 24 may be a positivedisplacement pump, such as a gear pump, vane pump, or progressive cavitypump.

An inlet 23 of the pump 24 may include a plurality of ports formedthrough the pump housing for allowing bitumen 8 p to enter a lower orfirst stage of the pump and a screen to filter particulates from theproduction fluid. Alternatively, the inlet 23 may be a separatecomponent, such as a bottom feeder having a housing and ported mandrelrotatable relative thereto and eccentrically weighted such that themandrel ports orient in response to gravity to face a bottom side of thehorizontal portion of the production wellbore 3 p. Alternatively, theinlet 23 may be a separate component, such as a static gas separator orrotary gas separator depending on the gas content of the bitumen 8 p.

The motor 20 may be an induction motor or a permanent magnet motor, suchas a brushless DC motor (BLDC). The motor 20 may be filled with adielectric, thermally conductive liquid lubricant, such as motor oil.The motor oil may have a density less than the bitumen 8 p. Inoperation, the motor 20 may rotate the motor shaft, thereby driving thepump shaft. The induction motor may be a two-pole, three-phase,squirrel-cage type and have a wound stator. The BLDC motor may be twopole and three phase. The BLDC motor may include a stator having thethree-phase winding and a permanent magnet rotor. The permanent magnetrotor may be made of one or more rare earth, ceramic, or ceramic-metalcomposite (aka cermet) magnets.

The motor driver 25 s may provide power and control to the motor 20. Themotor driver 25 s may include a rectifier 26 r, an inverter 26 i, aprogrammable logic controller (PLC) 26 c, and one or more sensors (notshown), such as a voltmeter and one or more ammeters. The motor driver25 s may receive a three-phase alternating current (AC) power signalfrom a utility grid or generator (not shown). The rectifier 26 r mayconvert the three phase AC power signal to a direct current (DC) powersignal and supply the converted DC power signal to the inverter 26 i.For the induction motor, the inverter 26 i may output a three-phasesinusoidal power signal at a variable frequency to control the speed ofthe motor 20.

For the BLDC motor, the inverter 26 i may have an output for each phase(i.e., three) of the motor 20 and may modulate the DC power signal todrive each phase of the stator 10 s based on control signals from thePLC 26 c. The sensors may measure voltage and current of one or more ofthe inverter outputs and be in data communication with the PLC 26 c. Forthe BLDC motor, the PLC 26 c may execute a program for commissioning themotor 20 to obtain necessary parameters for model-based backelectromotive force (BEMF) control of the motor. The PLC 26 c mayutilize data from the commissioning program to execute a BEMF model ofthe motor 20 for estimating a position of the rotor. The PLC 26 c mayuse the estimated rotor position to control the inverter 26 i such thatthe frequency of the power signals supplied to the stator windings matchthe frequency of the rotation of the magnetic field in the rotor. ThePLC 26 c may iteratively repeat the estimating and control in real time.

A surface cable may connect from the motor driver 25 s to the productionwellhead 2 p. The surface cable may connect to a penetrator at thewellhead 2 p. The penetrator may connect the surface cable to a downholecable 14 c. The downhole cable 14 c may extend down a length of theproduction tubing 12 t and may be fastened to the production tubing 12 tat various intervals. The downhole cable 14 c may terminate at a splice14 j. The splice 14 j may connect the downhole cable 14 c to a motorlead extension (MLE) cable 14 f. The MLE cable 14 f may be flat to fitin an annulus formed between the pump 24 and the casing 10 and/or liner13. The MLE cable 14 f may terminate at a pothead of the motor head 21.The pothead may be a connector assembly configured to connect the MLEcable 14 f to internal leads (not shown) connected to stator windings ofthe motor 20. Each cable 14 c, f may include a conductor for each phaseof the motor (e.g., three), one or more insulating layers for eachconductor, and an armor.

In one embodiment, a cable 105 is coupled to a body 110 of a pothead 60,as shown in FIG. 2. The cable 105 is suitable for use as a MLE cablesuch as cable 14 f. The pothead 60 is configured to connect the cable105 to a motor head 21. The cable 105 includes a plurality ofconductors, such as three conductors 55, for carrying three phase power.The body 110 of the pothead 60 includes three bores 93 for receivingeach of the three conductors 55. For sake of clarity, FIG. 2 shows onlyone of the conductors 55 disposed in its respective bore 93 of the body110. Each conductor 55 is made of copper.

One or more insulation layers capable of withstanding high temperaturesare disposed around the conductors 55. In one embodiment, a firstinsulation layer 122 made of polyimide is disposed around the conductor55. An exemplary polyimide layer is a layer of Kapton™, which ismanufactured by DuPont. A second insulation is provided by extruding afluoropolymer resin layer 127 around the polyimide insulation layer 122.An exemplary fluoropolymer resin layer is an epitaxial co-crystallizedalloy fluoroplastic resin layer, available from Chemours Company.

A thermoplastic insulator tube 128 is disposed around an end of thesecond insulation layer 127 and the first insulation layer 122. Theinsulator tube 128 may be made from a thermoplastic material capable ofwithstanding the high temperature environment. In one example, thethermoplastic material for the insulator tube 128 has a hardness(Rockwell A) range between 25 and 40 in accordance with ASTM D-785. Inone example, the insulator tube 128 is made from an extrudedglass-reinforced polybenzimidazole-polyetheretherketone (“PBI-PEEK”)blend material, such as Celazole®. In one embodiment, the end of thesecond insulation layer 127 is recessed to receive the insulator tube128. For example, the insulator tube 128 may be threaded onto the secondinsulation layer 127. In one embodiment, the insulator tube 128 isbonded to the second insulation layer 127 and the first insulation layer122. In another example, prior to bonding, the surface of thefluoropolymer containing second insulation layer 127 is treated by asodium-based solvent to extract the fluorine atoms at the surface of thesecond insulation layer 127. An exemplary sodium-based solvent is anetch solvent containing sodium naphthalide in glycol ether. In oneexample, the insulator tube 128 is bonded to the insulation layers 122,127 using a suitable epoxy, such as a cyclo-aliphatic two-part epoxy.

A metallic jacket 123 is disposed around the second insulation layer127. The metallic jacket 123 may be made from metals such as stainlesssteel, lead, or other suitable metals. An armor can be disposed aroundthe metallic jacket 123 and the plurality of conductors 55. In oneembodiment, the armor is a metallic armor, and it may be applied as, forexample, a helically wrapped metallic armor. In one example, theconductors 55 are arranged in a triangular configuration, although othersuitable configurations are contemplated, such as a flat configuration.

The metallic jacket 123 is arranged such that a portion of the secondinsulation layer 127 extends out from the end of the metallic jacket123. The insulator tube 128 attaches to the portion extending out of themetallic jacket 123. A metallic connector tube 90 is attached to the endof the metallic jacket 123. The connector tube 90 may be made from ametallic alloy and attached to the metallic jacket 123 using solder,thereby forming a seal 111 between the connector tube 90 and themetallic jacket 123. Suitable metallic alloys for the connector tube 90include a nickel-copper alloy such as Monel™. In one embodiment, theconnector tube 90 has a length between about 0.5 in. and about 5 ft.;preferably between about 0.5 in. and about 1 ft. In another example, theconnector tube 90 has a length between 1 ft. and 4 ft.

A metal fitting 85 is attached to a bore 93 of the body 110 usingthreads 88. In one embodiment, the metal fitting 85 is configured toform a metal-to-metal seal 137 with the body 110. In one embodiment, themetal fitting 85 includes a tapered surface for mating with a taperedsurface of the body 110. An optional secondary seal may be provided bydisposing a back-up O-ring 134 between the metal fitting 85 and the body110 and inwardly from the metal seal 137. The fitting 85 includes a bore186 for receiving the conductor 55. FIG. 2 shows the exposed portion ofthe insulation layer 122 and the connector tube 90 are at leastpartially inserted into the bore 186 of the metal fitting 85. Solder isused to attach the connector tube 90 to the metal fitting 85, therebyforming a seal 112. In this embodiment, a portion of the insulator tube128 is disposed inside the metal fitting 85.

A graphite containing sealing member 140 is employed to seal between thebody 110 and the conductors 55. As shown in FIG. 2, the graphitecontaining sealing member 140 is disposed in the bore 93 of the body 110and between the body 110 and the insulator tube 128. In one example, thegraphite containing sealing member 140 is in the shape of a ring. In oneembodiment, the graphite containing sealing member 140 comprisesflexible graphite. The flexible graphite optionally includes a metalwire embedded in the flexible graphite ring. The rings may be formedfrom a sheet of flexible graphite. A plurality of rings are disposednext to each other, and the insulator tube 128 is disposed through thehole of the rings. For example, a plurality of rings, such as two,three, four, five, six, seven, or more, may be stacked next to eachother. One or more of the plurality of rings may include an embeddedmetal wire. In one example, the ring stack may alternate between a ringwith metal wire and a ring without a metal wire. In another example, therings at each end include the metal wire, and the interior rings do not.In yet another example, the interior rings include the metal wire, andthe end rings do not.

A fastener 151 is used to compress and retain the plurality of graphitecontaining sealing members 140 in the bore 93. The fastener 151 made bemade of a corrosion resistant alloy such as a nickel-based alloy (e.g.,Monel®) or an iron-based alloy. The sealing members 140 may becompressed against a restriction in the bore 93. In one embodiment, anoptional washer 153 made of metal is disposed between the sealingmembers 140 and the fastener 151. The fastener 151 compresses thesealing members 140 sufficiently to form the desired seal with the body110 and the insulator tube 128. In one example, the sealing members 140are compressed between 10% and 40% of sealing members' 140 thickness. Inone embodiment, an elastomeric sealing member 131 is disposed betweenthe fastener 151 and the insulator tube 128. In one example, the sealingmember 131 is an O-ring made of an elastomer such as aperfluoroelastomer. An epoxy may be used to seal the threaded connectionbetween the fastener 151 and the body 110. An exemplary epoxy is acyclo-aliphatic two-part epoxy. The epoxy may prevent leakage of thegraphite particles and loosening of the threaded connection.

A male terminal 75 is attached to the end of the conductors 55. Theterminal 75 may be made of brass and connected directly to the conductor55 using a threaded connection. The terminal 75 is configured totransfer power from the cable 105 to the motor 20.

An insulator cap 65 is disposed around the three male terminals 75, aportion of the conductors 55, and a portion of the insulator tube 128.The insulator cap 65 may be made of a hard plastic having a hardness(Rockwell A) range between 25 and 40 in accordance with ASTM D-785. Inone embodiment, the insulator cap 65 and the insulator tube 128 are madeof the same material. The insulator cap 65 is configured to insulate theterminals 75 from the body 110. The interior end of the insulator cap 65is disposed inside the bore 93 and between the body 110 and theinsulator tube 128. The insulator cap 65 includes three openings forreceiving each of the three conductors 55. An optional snap ring is usedto retain the insulator cap 65 in position. In this respect, theposition of the insulator cap 65 is fixed between the body 110 and thesnap ring.

An end cap 106 is attached to the body 110 and extends over at least aportion of the connector tubes 90. The space in the end cap 106 may befilled with an epoxy. The epoxy may help stabilize the conductors 55against movement at their connection with the body 110.

To connect the cable 105, the body 110 is attached to the motor head 21.Two sealing members 161 are disposed in a groove 67 of the body 110 andare engageable with the motor head 21. An exemplary sealing member 161is an elastomeric O-ring such as perfluoroelastomer or EPDM. The sealingmembers 161 close off fluid communication between the body 110 of thepothead 60 and the motor head 21.

A cable system for use downhole includes a connector assembly having abody and a bore formed therethrough; a conductor disposed through thebore of the connector assembly; a first insulation layer disposed aroundthe conductor; an insulator tube disposed around the conductor andhaving an end attached to the first insulation layer, the insulator tubecomprising a thermoplastic material; and a graphite containing sealingmember disposed in the bore and disposed between the insulator tube andthe body of the connector assembly.

In one or more of the embodiments described herein, the cable systemalso includes a fastener configured to apply a compressive force againstthe graphite containing sealing member.

In one or more of the embodiments described herein, the cable systemalso includes an elastomeric sealing member disposed between thefastener and the insulator tube.

In one or more of the embodiments described herein, the cable systemalso includes a metal fitting attached to a bore surface of the body,the metal fitting forming a metal-to-metal seal with the body.

In one or more of the embodiments described herein, the cable systemalso includes an elastomeric sealing member disposed between the fittingand the body.

In one or more of the embodiments described herein, the cable systemalso includes a connector tube disposed around the first insulationlayer, wherein the connector tube is sealingly attached to the fitting.

In one or more of the embodiments described herein, the cable systemalso includes a metal jacket disposed between the first insulation layerand the connector tube, wherein the connector tube is sealingly attachedto the metal jacket.

In one or more of the embodiments described herein, the cable systemalso includes a second insulation layer disposed between the firstinsulation layer and the conductor.

In another embodiment, a submersible pumping system for use downholeincludes a motor; a pump powered by the motor; a tubing connected to thepump; and a cable disposed along the tubing and configured to providepower to the motor. In one embodiment, the cable includes a connectorassembly having a body and a bore formed therethrough; a conductordisposed through the bore of the connector assembly; a first insulationlayer disposed around the conductor; an insulator tube disposed aroundthe conductor and having an end attached to the first insulation layer,the insulator tube comprising a thermoplastic material; and a graphitecontaining sealing member disposed in the bore and disposed between theinsulator tube and the body of the connector assembly.

In one or more of the embodiments described herein, the pumping systemalso includes a fastener configured to apply a compressive force againstthe graphite containing sealing member.

In one or more of the embodiments described herein, the pumping systemalso includes a metal fitting attached to a bore surface of the body,the metal fitting forming a metal-to-metal seal with the body.

In one or more of the embodiments described herein, the pumping systemalso includes a connector tube disposed around the first insulationlayer, wherein the connector tube is sealingly attached to the fitting.

In one or more of the embodiments described herein, the pumping systemalso includes a metal jacket disposed between the first insulation layerand the connector tube, wherein the connector tube is sealingly attachedto the metal jacket.

In one or more of the embodiments described herein, the connector tubehas a length between 0.5 in. to 5 ft.

In one or more of the embodiments described herein, a plurality ofgraphite containing sealing members are stacked next to each other.

In one or more of the embodiments described herein, at least one of thegraphite containing sealing members include a metal wire.

In one or more of the embodiments described herein, the plurality ofgraphite containing sealing member have a ring shape.

In one or more of the embodiments described herein, the first insulationlayer is treated by an etch solvent before the insulator tube isattached to the first insulation layer.

While the foregoing is directed to certain aspects of the presentdisclosure, other and further aspects may be devised without departingfrom the basic scope thereof, and the scope thereof is determined by theclaims that follow.

What is claimed as the invention is:
 1. A cable system for use downhole,comprising: a connector assembly having a body and a bore formedtherethrough; a conductor disposed through the bore of the connectorassembly; a first insulation layer disposed around the conductor; aninsulator tube disposed around the conductor and having an end attachedto the first insulation layer, the insulator tube comprising athermoplastic material; and a graphite containing sealing memberdisposed in the bore and disposed between the insulator tube and thebody of the connector assembly.
 2. The cable system of claim 1, furthercomprising a fastener configured to apply a compressive force againstthe graphite containing sealing member.
 3. The cable system of claim 2,further comprising an elastomeric sealing member disposed between thefastener and the insulator tube.
 4. The cable system of claim 1, furthercomprising a metal fitting attached to a bore surface of the body, themetal fitting forming a metal-to-metal seal with the body.
 5. The cablesystem of claim 4, further comprising an elastomeric sealing memberdisposed between the fitting and the body.
 6. The cable system of claim4, further comprising a connector tube disposed around the firstinsulation layer, wherein the connector tube is sealingly attached tothe fitting.
 7. The cable system of claim 6, further comprising a metaljacket disposed between the first insulation layer and the connectortube, wherein the connector tube is sealingly attached to the metaljacket.
 8. The cable system of claim 7, further comprising a secondinsulation layer disposed between the first insulation layer and theconductor.
 9. The cable system of claim 4, wherein the connector tubehas a length between 0.5 in. to 5 ft.
 10. The cable system of claim 1,wherein a plurality of graphite containing sealing members are stackednext to each other.
 11. The cable system of claim 10, wherein at leastone of the graphite containing sealing members include a metal wire. 12.The cable system of claim 10, wherein the plurality of graphitecontaining sealing member have a ring shape.
 13. The cable system ofclaim 1, wherein the first insulation layer is treated by an etchsolvent before the insulator tube is attached to the first insulationlayer.
 14. A submersible pumping system for use downhole, comprising: amotor; a pump powered by the motor; a tubing connected to the pump; anda cable disposed along the tubing and configured to provide power to themotor, the cable comprising: a connector assembly having a body and abore formed therethrough; a conductor disposed through the bore of theconnector assembly; a first insulation layer disposed around theconductor; an insulator tube disposed around the conductor and having anend attached to the first insulation layer, the insulator tubecomprising a thermoplastic material; and a graphite containing sealingmember disposed in the bore and disposed between the insulator tube andthe body of the connector assembly.
 15. The submersible pumping systemof claim 14, further comprising a fastener configured to apply acompressive force against the graphite containing sealing member. 16.The submersible pumping system of claim 14, further comprising a metalfitting attached to a bore surface of the body, the metal fittingforming a metal-to-metal seal with the body.
 17. The submersible pumpingsystem of claim 16, further comprising a connector tube disposed aroundthe first insulation layer, wherein the connector tube is sealinglyattached to the fitting.
 18. The submersible pumping system of claim 17,further comprising a metal jacket disposed between the first insulationlayer and the connector tube, wherein the connector tube is sealinglyattached to the metal jacket.
 19. The submersible pumping system ofclaim 17, wherein the connector tube has a length between 0.5 in. to 5ft.
 20. The submersible pumping system of claim 14, wherein a pluralityof graphite containing sealing members are stacked next to each other.21. The submersible pumping system of claim 20, wherein at least one ofthe graphite containing sealing members include a metal wire.
 22. Thesubmersible pumping system of claim 20, wherein the plurality ofgraphite containing sealing member have a ring shape.
 23. Thesubmersible pumping system of claim 14, wherein the first insulationlayer is treated by an etch solvent before the insulator tube isattached to the first insulation layer.